fix(fc): tiny white border on highlighted cells

[st3iny]

Fixes #6139

Before	After

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 23.97%. Comparing base (6d1a23d) to head (1017e40).
Report is 28 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #6171      +/-   ##
============================================
- Coverage     23.97%   23.97%   -0.01%     
  Complexity      457      457              
============================================
  Files           247      247              
  Lines         11605    11606       +1     
  Branches       2177     2188      +11     
============================================
  Hits           2782     2782              
- Misses         8508     8509       +1     
  Partials        315      315              

Flag	Coverage Δ
javascript	15.46% <ø> (ø)
php	59.53% <ø> (-0.03%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[ChristophWurst]

Is it safe to backport? Prod has a border right as well

[st3iny]

Yeah, it's safe to backport. I checked locally.

[st3iny]

/backport to stable4.7